What field is used to pass on transaction information? input field or data field?

In the documentation here under the eth_sendTransaction, it shows/states that in the transaction object sent, there is an input field.

But in the documentation here it says there is a data field.

My question is, which is correct? When crafting a transaction object, under what field should information about arguments and which methods on the smart contracts to be invoked included in? data field? or input field?